Return-Path: Received: from mtain-dg07.r1000.mx.aol.com (mtain-dg07.r1000.mx.aol.com [172.29.65.15]) by air-dc10.mail.aol.com (v127_r1.1) with ESMTP id MAILINDC103-86564b85489e1d8; Wed, 24 Feb 2010 10:41:18 -0500 Received: from post.thorcom.com (post.thorcom.com [193.82.116.20]) by mtain-dg07.r1000.mx.aol.com (Internet Inbound) with ESMTP id ABD4D380000C1; Wed, 24 Feb 2010 10:41:16 -0500 (EST) Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1NkJKr-0005jI-34 for rs_out_1@blacksheep.org; Wed, 24 Feb 2010 15:39:37 +0000 Received: from [193.82.116.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1NkJKq-0005j9-Im for rsgb_lf_group@blacksheep.org; Wed, 24 Feb 2010 15:39:36 +0000 Received: from lnx500.hrz.tu-darmstadt.de ([130.83.156.225]) by relay1.thorcom.net with esmtp (Exim 4.63) (envelope-from ) id 1NkJKo-0004xO-Lf for rsgb_lf_group@blacksheep.org; Wed, 24 Feb 2010 15:39:36 +0000 Received: from FILE-SERVER-HST.hst.e-technik.tu-darmstadt.de (File-Server-HST.hst.e-technik.tu-darmstadt.de [130.83.212.129]) by lnx500.hrz.tu-darmstadt.de (8.14.2/8.14.2/HRZ/PMX) with SMTP id o1OFdUZu003513 for ; Wed, 24 Feb 2010 16:39:31 +0100 (envelope-from schaefer@hst.tu-darmstadt.de) Received: from [127.0.0.1] (helo=File-Server-HST.hst.e-technik.tu-darmstadt.de) by FILE-SERVER-HST.hst.e-technik.tu-darmstadt.de with AVK MailGateway; for ; Wed, 24 Feb 2010 16:39:31 +0100 Content-class: urn:content-classes:message MIME-Version: 1.0 X-MimeOLE: Produced By Microsoft Exchange V6.5 Date: Wed, 24 Feb 2010 16:39:31 +0100 Message-ID: <38A51B74B884D74083D7950AD0DD85E82A1B17@File-Server-HST.hst.e-technik.tu-darmstadt.de> X-MS-Has-Attach: X-MS-TNEF-Correlator: <38A51B74B884D74083D7950AD0DD85E82A1B17@File-Server-HST.hst.e-technik.tu-darmstadt.de> Thread-Topic: AW: LF: VLF_8.79 kHz_grounding systems Thread-Index: Acq1XtrVOstxxtzYQky2OMjZDpYmwgAB/0bJ References: From: =?iso-8859-1?Q?Stefan_Sch=E4fer?= To: X-AVK-Virus-Check: AVB 19.717;31.01.2010 X-PMX-TU: seen v0.99a by 5.5.9.388399, Antispam-Engine: 2.7.2.376379, Antispam-Data: 2010.2.24.153053 X-PMX-SPAMCHECK: outgoing mail X-Spam-Score: 0.0 (/) X-Spam-Report: autolearn=disabled,none Content-Type: multipart/mixed; boundary="----_=_NextPart_001_01CAB567.8EAA01F8" Subject: AW: AW: LF: VLF_8.79 kHz_grounding systems X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: X-Spam-Status: No, hits=0.0 required=5.0 tests=none autolearn=no version=2.63 X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false x-aol-global-disposition: G X-AOL-VSS-INFO: 5400.1158/55453 X-AOL-VSS-CODE: clean x-aol-sid: 3039ac1d410f4b85489c78b7 X-AOL-IP: 193.82.116.20 X-Mailer: Unknown (No Version) ------_=_NextPart_001_01CAB567.8EAA01F8 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hello Alexander,=20 Let us see what will happen if you cancel out that 100nF Cp:=20 The overall C in the circuit is the C of the antenna, 1nF, so you need abo= ut 100* the L before. If we assume now, the resistance of L is 100 Ohm, th= e overall resistance in the circuit is abt 1100 Ohm. Applying the same pow= er than before (Pin=3D1,1W (ground+coil loss before)) will give a current= of 32mA =3Dsqrt(10) * I antenn before and thus the "radiated" signal is= 10 dB stronger than before, although the coil losses are 100* more, right= ?=20 73, Stefan/DK7FC=20 ________________________________ Von: owner-rsgb_lf_group@blacksheep.org im Auftrag von Alexander S. Yurkov Gesendet: Mi 24.02.2010 22:35 An: rsgb_lf_group@blacksheep.org Betreff: Re: AW: LF: VLF_8.79 kHz_grounding systems >=20 > So, the coil losses decrease with it's L (assuming a given wire diameter= , > coil diameter and spacing and so on) and thus it is good to decrease the > needed L. You can decrease L only by condenser in parallel with a antenna. But then only part of coil current will flow thrue the ant (and ground stake also). Let's describe some numerical example. Let antenna capacity (denoted as Ca) is 1 nF (large antenna!). Resistance of grounding we assume 1000 Ohm (huge resistance!). Parralel C (Cp) we assume to be 100 nF. Then L=3D3= .2 mH. Let coil resistance is 1 Ohm (large coil!) and coil current I is 1 A. Then coil loss is 1 W. Antenna current for Ca<